A Trick Of The Light
by APerfectGrace
Summary: Four times. Four times Sam witnesses something strange happen between Dean and Cas, things that make him start to believe that there is something going on between the two of them. Something... romantic. One shot. Spoilers for all seasons.


_Hellohellohello._

_In keeping with the origin of a lot of my stuff lately, this came about with a random thought I had about the little moments that would occur between Dean and Cas if they realised their love for each other and became loverrrrrrs._

_Cute, fluffy Destiel. Come and bask in the cotton-candy goodness._

_**WARNING:**__ SPOILERS FOR ALL SEASONS. BE WARNED._

___**Note:**__ This is set at some point in early Season 9, before Cas becomes an angel again. The April storyline never occurred in this story._

_**Disclaimer:**__ I don't own anything Supernatural-related. _

* * *

The first time something happened, it was so fleeting that he simply passed it off as a trick of the light. The second time, he was sure that his mind was playing tricks on him and that he was more out of whack from Ezekiel than he realised. The third time that he saw something-that-didn't-happen, either it was a _really_ good coincidence, or maybe, just maybe, he actually _was _seeing what he was seeing. The fourth and final time, he was absolutely positive, without any shadow of a doubt: his psychotic, gun-slinging brother and the socially awkward nerdy dude with the feathers were seriously into each other and shacking up. _Big_ time.

It had been a gradual change – slow, subtle, deliberating. Inconspicuous enough to fly under his radar at first, but then, when the small leaks of affection began to grab his attention…

And now… _boy_, he was so honed in on it that he could clock an upcoming Destiel moment from two miles away. Once he'd picked up on it, he couldn't _stop_ seeing it. It was one of those things that became stupendously obvious once realised and then constantly obvious because it was a _behind-the-scenes-there-all-the-time-and -it-actually-makes-sense-all-along_ thing.

Sam wasn't quite sure when things had changed between Dean and Castiel – the timeframe was fuzzy.

Maybe it was before Cas lost his grace. Maybe while they were in Purgatory? Or perhaps before Cas had his mini God-complex episode and Leviathans played 'here's Johnny' in his body. Possibly before Bobby? Hell, maybe it was there all along, the moment those barn doors opened and Cas strode in with his ice eyes and his smouldering look and the _huge black wings_, and Dean discovered that it was _him_ who 'raised him from perdition'.

Either way, regardless of when it transpired, the point was that it had _happened_.

The two were still as close as ever, but the dynamics of their relationship had definitely shifted into something else, something that Sam was pretty sure blurred the not-so-straight-edged lines between friendship and romantic feelings.

Truthfully, Sam didn't think Dean even _thought_ about stuff like that. Hell, he didn't even have time to tie his laces, let alone get into a long-term relationship with someone. Neither did Sam, if he was being honest. With a life like theirs, feelings just made things problematic. Lisa, Ben, Jess, Amelia… they were all examples of that. Life was just too complicated and chaotic right now for anything more than a great night, cheap alcohol, hasty morning goodbyes and fond memories.

And while he was thinking about it, he didn't even consider that _Castiel_ knew about those types of relationships, let alone participate in them. Sure, he had managed to successfully integrate himself into their band of not always brotherly love, but that had come complete with the standard angel package: social awkwardness, pig-headedness, misunderstandings and some seriously fucked up life choices. Still, Cas was their closest friend now, and he theirs; although, in Dean's case, it seemed to be _way_ more than friendship.

It was like the universe had picked the world's worst two people (and he used that term loosely, especially in Cas's case) in terms of relationships and slapped them together with a binding rope of confusion and desire. Dean, whose only long-term relationship was with a baked dessert, and Castiel, a virginal angel of the Lord who didn't understand pop media references. A sarcastic, trigger-happy dude who walked in and out of hell like it was his summer house, and a consistently confused angel who caused more destruction than an epidemic virus. It was so funny that it didn't seem real. Fairy tales, Winchester style.

He reckoned that he first noticed it approximately a month ago.

They had been sitting at the table of the bunker one morning – Sam and Dean had been researching anything that they could about jump-shooting the 'wingless dicks' back to Heaven, while Cas had been interrogating Crowley on something involving the spell used to deep-fry his grace.

Dean was shovelling mouthfuls of breakfast down his throat whilst scanning a book that analysed the Old Testament; Sam had just finished the third of seven volumes on the many, many different philosophical theories based on angel lore. It was an uncommon, yet comfortable silence, and Sam savoured it. Truth be told, life was so crazy that the small bubbles of peace and quiet were like a rare delicacy.

It was at this precise moment that Cas entered the room, having taken a small break from His Royal Sarkiness in order to find a particular book that would assist him. He greeted the Winchesters, to which they returned the favour. After a brief conversation with Sam on the current status of his talk with Crowley (fruitless as always, although it turned out that the King of Hell was more than eager to offer his help when it came to Abaddon and the whole taking his throne idea), Cas headed over to the religion section situated behind Dean.

He walked past the older Winchester and moved straight over to the rows of books that adorned the heavy wooden bookshelves. After a minute of searching, he spotted what he needed: a particularly large, navy volume coated in a thick film of dust. He picked it up, quickly leafing through it, lost in his own thoughts.

He shut the book and turned back to the way he had come, tucking the volume under his arm and bypassing an engrossed Dean once more. As he did so, without so much as turning to face him, Cas raised a hand and let it lazily brush the underside of Dean's chin, the fingers gently stroking his face in a lingering touch that was both abnormally affectionate and out of character for him. One moment, his fingertips were softly grazing the smooth skin, the next moment both Cas and his wandering hands were gone as he walked past and abruptly left the room.

Sam stared, dumbstruck.

Dean didn't even balk at the unexpected touch, instead just reading on without as much as a reaction.

Did Cas just…?

Sam could have sworn that, for a split second, the corner of Dean's mouth twitched into a smirk, but it was gone before he could even do a double take.

He hadn't realised that he had been staring into space with an astounded expression until a piece of bread flew past his line of vision, snapping him back to reality.

"Sammy! I've been calling your name for five minutes now, are you okay?" Dean asked loudly, calling him as if from a distance. Concern was etched in the lines on his face.

"Huh? Oh, yeah, fine," he said in a daze, resuming his reading. He could feel Dean's gaze on him, but kept his eyes low, thoughts stirring.

What the hell was _that?_ Did Cas lose vital brain cells when he lost his grace? Did Dean have a transplant that rendered him incapable of noticing events out of the ordinary? Why didn't he_ do_ anything?

That type of action would not be out of place in, say, a romanticised relationship between two people who were sexually and emotionally attracted to each other. But Dean and Cas didn't see each other that way… right?

It was so out of the ordinary that Sam was convinced that it had just been a split-second illusion and that maybe it was time for a lie-down to rest his hallucinating mind. All the recent events had scrambled his mind and he was just probably tired and in need of a serious battery recharge.

Yeah. That was it. He hadn't seen anything odd. Nothing at all.

That is, until the next time that it happened.

It occurred a week later. They had been travelling in the Impala – rumours had made their way to Team Freewill about a pack of werewolves in a small town in Oregon. They had driven up there and were now presently in said town, investigating into all the details of the latest attack in an effort to stop these assholes.

Sam was currently interviewing a witness who had discovered the body, Dean was in the house checking for leads to the werewolves and Cas was consulting with the police officers on the scene. The witness – the victim's young wife – was tearfully recalling what she found as Sam scribbled a few vital points into a small notepad while offering his condolences.

As he looked up from his notes, he happened to glance over the woman's shoulder and saw Cas making his way back to the Impala, having finished with the authorities. Dean wasn't far behind him, his search in the house now completed. As he neared him, his strides slowed down to match that of the angel's and he unexpectedly leant sideways to whisper something in his ear, something that garnered a surprising reaction from Cas. The angel smiled: a small, yet extremely endearing smile that seemed to illuminate his entire face. The way that his lips curved upwards, coupled with the momentary look he shyly directed towards his brother, the glance that said a million unspoken things, were definitely, definitely _not_ in keeping with the obstinate Cas that Sam knew. And _Dean_… Dean was mirroring the angel's reactions: a half-lidded, tender gaze aimed at him and an unknown emotion hidden behind his grin.

What… the… _hell?_

"I beg your pardon?" It wasn't until the woman asked this that Sam realised that he had voiced his thought out aloud.

He apologised profusely and fabricated a quick excuse, all the while keeping his eye on the other two members of his team. However, by then the moment had dissipated and they were getting into the car. Frustrated, Sam wrapped things up and headed over to the Impala, wondering if the sun beating down on his head was causing visual hallucinations and vowing to make sure that he was a hundred per cent on the next job, because these pseudo-Dean and Cas moments were starting to do his head in.

The third and fourth times coincided on the same day, three days later.

They had just finished the Oregon job, and were settling down for the night before heading back to the bunker in the morning. Dean was in the restroom washing his hands, and Sam was on the bed, resuming his research for Project Revive Heaven. They were waiting on Cas, who had popped down the road for supplies and was going to be back at any moment.

Speak of the devil… The hotel lock clicked and the door pushed open, revealing the angel holding an abundance of carrier bags.

"Took you long enough," Dean commented lightly, exiting the restroom whilst drying his hands on a towel.

"There were many provisions to purchase, Dean," Cas replied, the sarcasm sailing over his head as he dumped the bags on the nearby coffee table.

Sam placed his laptop on the bed and got up, heading over to the table at the same time as Dean threw the towel on the rack and moved towards the pile of shopping. Cas was already unpacking – they began to aid him and empty the bags.

"Where's the –"

Dean never managed to get through the rest of his sentence, instead being met face-to-face with a pie the size of a small country that Cas was currently thrusting at him. He was so predictable, sometimes.

"Cas, you're _awesome_," he said fervently, snatching it out of his hands and ripping the plastic packaging open without an ounce of elegance.

Sam caught the faint wisp of something gentle laced into the excitement of Dean's voice, something that was both calm and loving, something that he seemed to be directing at Cas a lot lately. Cas, and_ only _Cas.

"Thank you, Dean," he responded, and he heard it in the angel's tone too.

Great, now he was having auditory as well as visual delusions?

Except he wasn't.

Sam wasn't an arrogant guy; he was more than aware of his flaws and limitations, and furthermore was man enough to admit them. However, he also knew his strengths too, and there were two that very much applied to this instance: firstly, he was able to pick up on all the minute details of any given situation (like a modern day Sherlock Holmes, without the drugs), and secondly, his gut was pretty much on point with ninety-nine per cent of things.

And his instinct was telling him one thing: he was certainly _not_ imagining all of this.

The face-touching, the smiling, the soft tones…

Once may have been a trick of the light, and twice may have been a happy coincidence, but thrice was definitely a charm.

It was official.

Dean and Castiel had definitely become something _way _more than friends.

Suddenly, he was snapped out of his reverie at the sight of something that just confirmed the conclusion that he had come to.

Cas was unpacking the last bag, and as he dipped his left hand into the plastic, the sleeve of his coat snagged against one of the containers nestled inside. This pushed the fabric up ever so slightly, but it was enough for Sam to catch a glimpse of something underneath his sleeve: fool-proof evidence.

Wrapped around the angel's slender wrist was his brother's favourite leather bracelet.

It was dark brown in colour, and faded in some areas, with a silver clasp adorning the end of it, and it was_ definitely _Dean's. Sam could recognise that piece of jewellery from the other side of the country.

It was Dean's bracelet. And _Cas _was wearing it.

That was all the instigation that he needed.

His arm suddenly darted out and clamped a hand around the angel's wrist, the offending object shaking precariously with the sudden movement. Cas nearly dropped a carton of milk as he blinked up at him, shock behind his expression at the swift outburst. Dean had stopped inhaling pie and was now staring at the unfolding situation with a mixture of confusion and apprehension, the half-eaten pie frozen in front of his mouth in a comical picture.

"What the hell is this?" Sam demanded whilst eyeing him, the grip on his wrist gentle but firm.

"What… what is what, Sam?" Cas asked, confused and taken aback at the tone of his voice. He was too stunned to try and escape from his grasp.

"Sam –"

The younger Winchester held his hand up, silencing his brother. If this wasn't such an alien thing for him to do, Dean might have yelled at him and tried to punch him, but as it happened, he just put the pie down, his body rigid and poised for something. Maybe he thought Sam had lost his marbles.

Sam did not fail to notice the way Dean had tensed up when he had grabbed Cas, panic flashing across his eyes, combined with something that seemed to Sam to be a lot like possessiveness.

Oh, yeah… he was totally right. And he was going to enjoy pulling the truth out of them.

"_This,_" he emphasised, snaking the tip of a finger under the smooth leather and drawing Cas's attention towards it, before shooting a look at Dean. The air of his voice suggested that he wasn't just referring to the jewellery, but rather the two of them in general. He highlighted this point by gazing pointedly from one to the other.

When he realised what Sam was implying, Castiel's eyes widened a fraction before he tried to hide the sudden burst of anxiety that bubbled up in his chest. It was useless; Sam saw it and added it to the ever growing list of evidence that Dean and Cas had a hell of a profound bond going on.

"Sam, we have no idea what you're talking about," Dean said finally, his eyes focused on the unrelenting grip on Cas's arm.

"Since when do you ever give people your stuff to wear, Dean?"

Dean coloured in response, and it felt like he had found all the missing pieces to a puzzle he had forgotten that he had. "I... I don't know what you're making a fuss about, dude. It's a freaking bracelet." Which would have been semi-believable, if not for the increased tempo of his words and the red blush creeping up underneath his collar. Cas was swallowing hard, his Adam's apple bobbing up and down nervously.

Wow, this was too easy. Sam was going to have to pull hard. With pliers.

"Okay," he answered with fake impatience, releasing the angel's hand. Dean's shoulders visibly relaxed and Cas hastily pulled the sleeve of his trench coat back down. "Let me put this in a blunt way that even the pair of you will understand. You two are quite obviously together, in a till-death-do-us-part way. Don't even bother denying it. When did you two become a couple?"

There. He said it. A silence descended in the atmosphere unlike anything he had known. There were no words for how deafening and severely uncomfortable it was. Both Dean and Cas looked like they wanted nothing more than the ground to swallow them whole. Which was just even more incriminating really, because if it wasn't true, they would have vehemently denied it and probably chucked something at him. Instead, they were looking everywhere but at him, and their flushes were hot enough to fry eggs on.

"I… I don't –"

"I've been watching you both for quite some time now. I've seen the smiles, the touches, and now _this_ –" he gestured to Castiel's little accessory, loving the way that they both flushed at his revelation that he had been cataloguing their little moments. "Swapping jewellery? Do I look like an idiot to you?"

Cas cleared his throat, trying to find his voice. "Sam –"

He ploughed on, determined to make this as uncomfortable for them as possible. "So what did _you_ give Dean, Cas, huh? A necklace?"

"Yes," he replied simply, unable to meet his gaze.

"I mean – wait, what?" Well, he wasn't expecting _that_.

The angel shifted from one foot to the other, uncomfortable. Meanwhile, Dean had a face like thunder coupled with a complexion which basically resembled that of a tomato.

"Before angels are created, our grace is born first. It is kept with God until it is time for Him to bring us into existence. It is kept in a small vial, each vial destined for one angel and one angel only. Each vial is different for each angel, similar in the way that each human being has their own genetic code. When we are then brought into fruition, we are given our grace, but we are unable to bond to it until we reach adulthood, because our forms are not fully completed. We keep our vials with us at all times until the day of our maturity. Similar to a bar or bat mitzvah, we go through a ceremonious occasion where we are bonded with our grace. A celebration into becoming fully fledged angels, if you will. Becoming bonded with my grace was one of the proudest moments of my life, Sam. I gave the necklace to your brother because it is very important to me, and I wanted him to have it."

Sam turned to Dean, who was looking at him with a grim expression. Slowly, he reached up to his neck and pulled out a thin, silver chain that had been hidden under his shirt. Dangling at the end of it was a small, delicate vial, engraved with tiny Enochian symbols. The glass reflected the light from the ceiling, making it shimmer, and it swung softly from his hand, like a pendulum. After a moment, he carefully tucked it back into his shirt which an alarming gentleness that was unbefitting for someone like Dean. He treated it like it was precious. Which it was. Cas had given it to him.

There was so much history and emotion that had transpired in the last few minutes that Sam suddenly felt dizzy. The urge to sit down was overwhelming, and he collapsed into the chair next to him, trying to process everything. "You still haven't answered my question."

It was still unbearably awkward; the tension in the room could have been cut with a steak knife. Dean was leaning against the back of a chair with his gaze cast downward, and Cas was looking anywhere but Sam.

Then, out of nowhere, without so much as lifting his head, Dean's hand rose from the smooth wood of the chair and reached out to snake around Cas's arm, before sliding down to entwine the angel's fingers with his own. This was met with no resistance on the angel's part; Cas's fingers curled around Dean's without a second thought, like it was second nature.

And in that instance, Sam _knew_.

Dean and Cas were together, in every sense of the word. Together, a couple, boyfriend and boyfriend, whatever it was people were calling it these days. But it was unequivocally there. It wasn't shout-from-the-rooftops obvious, and that was fine. It was private, it was secret, but it was theirs.

"I don't want to fight, Sam," Dean said in a low voice, his resolution set and his mind seemingly made up about something that he couldn't figure out. "But this is… this is what it is. Us. We're together, we have been for a while now, but we are not going back to how things were. And I'm sorry you don't like this, I am, but –"

"What?" he replied, stumped.

"You don't agree with us," Cas surmised, his hold on Dean's hand both tight and loving at the same time.

"When did I say that?"

Now it was Dean and Castiel's turn to be bewildered. They shot a furtive look at each other.

Sam felt like laughing. He folded his arms, sat back and regarded them slowly. "I'm not pissed that you're together. Do you think that's why I'm upset?"

"Aren't you?" Cas asked, his eyes narrowed in that way he did when he had no idea what was going on.

"No. Honestly, it makes a lot of sense. I'm kind of annoyed I didn't see it sooner, actually. But that's not why I'm upset."

"Then why?"

"Because you didn't tell me!" he shouted. "What, were you going to hide this from me forever?"

They both had the decency to look ashamed. Then, they were both talking at the same time, stumbling over their words and each other.

"No –"

"It wasn't like that –"

"We just –"

"We didn't know how to tell you, Sammy."

"How about: 'hey, Sam, I've realised that I kinda have a thing for dudes that I never told you about and oh, by the way, Cas and I are doing the naked tango now'?"

Dean made a strangled noise, and Cas cocked his head to the side. "Naked tango is a euphemism for sex, correct?"

If the older Winchester could turn any more red, his head was going to explode. "_Yes,_ Cas. Now, shut up."

"Sorry."

"I don't have a thing for dudes!" He aimed this at Sam, who raised an eyebrow and pointed to their entwined hands. "No?"

Watching Dean die of embarrassment was quite possibly the best thing he had ever seen. "N-No, I mean… I don't mean this – I mean… I don't like all of them! Just… just Cas."

Sam was not easily brought to tears, but the simple yet soft way in which Dean just said that, coupled with the adoring gaze that Cas gave him in response, _and_ the little squeeze of his fingers, was just about the cutest thing that he had _ever_ seen. He suddenly had this ridiculous urge to _squeal._

Forcing this weird impulse down, he observed the pair of them, his face a mask. "So, I think I'm entitled to know everything about you two now, especially considering since you kept it such a secret from me. I thought we told each other everything."

"Sam," Dean groaned, the guilt trip working hard and fast.

"Don't. I thought we all trusted each other, but clearly, I was wrong."

"_Sam_," Cas implored, a pleading expression written across his features.

He was inwardly grinning, determined to make them feel as awkward as possible. He wasn't lying when he said that it didn't bother him. They lived in the twenty-first century, didn't they? Love was love, whether it was between man and woman, woman and woman, or man and angel sporting male vessel. Dean deserved to be happy, and if Cas was the one who gave that to him then there was no way in hell that Sam was standing in the way of that. The same went for Cas; if his idea of a partner was Sam's arrogant, pie-scoffing, ripped-jeaned brother, then he would give them his sincere blessing.

But not for a while. They still kept it hidden from him, and for that, he was going to make them suffer. Badly.

He settled down in his chair, staring up at them. They glanced at each other, nervous and intimidated and frightened and looking like deer caught in headlights.

Sam smirked inwardly. Oh, he was just getting _started._


End file.
